Although Mil was a high prospect for the Mexican Olympic Judo team, he decided in 1965 to become a professional luchador. Within five years he would become one of the most celebrated wrestlers in Mexico and internationally. His legendary career has been recognized in many ways around the world, including in the United States with his induction into the Pro Wrestling Hall of Fame (New York) and the WWE Hall of Fame. Below is a quote from fellow Hall-of-Fame wrestler Dick Beyer in an excerpt from the book, The Pro Wrestling Hall of Fame: Heroes and Icons (Johnson, Oliver, Mooneyham, and Dillon):

"Of all the wrestlers that I ever wrestled against, Mil Mascaras was the toughest, best-conditioned," Beyer said at a 2010 Pro Wrestling Hall of Fame speech. "When I want to watch a wrestling match at home, I take out a wrestling match where I wrestled against Mil Mascaras. And I can still get excited because Mil Mascaras was a wrestler who never gave you a hold. I learned quick that if he wasn't going to give me a hold, I wasn't going to give him a hold. We went sixty minutes in Japan, and in the Olympic Auditorium in Los Angeles, with the same type of match. We never talked in the ring. It just came as the match went along.

The refined and patrician Mascaras, who rarely resorted to rule-breaking and used his repetoire of moves and counter-moves, was an innovator and trendsetter inside the ring who introduced aerial maeuvers such as planchas, topes, and suicide dives to new audiences. His visage routinely graced the covers of the era's top wrestling magazines.